Xinhua, China’s state-run news agency, issued an unusual public apology for publishing a doctored photograph of Tibetan wildlife frolicking near a high-speed train. The deception — uncovered by Chinese Internet users who sniffed out a Photoshop scam in the award-winning picture — has brought on a big debate about media ethics, China’s troubled relationship with Tibet, and how pregnant antelope react to noise. The photo was the work of Liu Weiqing, a 41-year-old photographer who had been camped with his Jeep on the Tibetan plateau since March, as part of a highly publicized series by the Daqing Evening News, a regional newspaper, to raise awareness of the rare Tibetan antelope. Mr. Liu was also under contract with Xinhua to provide photos for China’s largest government-run news service.